Apparatus for examining gems and crystals



Jam l0, 1950 H. L. WOODRUFF 2,49478 APPARATUS F'OR EXAMINING GEMS AND CRYSTALS Filed April 26, l94 8 2 Sheets-Sheet l Jam., l, 150 H. L. WooDRUr-'F 294:9473

APPARATUS FOR EXAMINING GEMS AND CRYSTALS Filed April 26., 1948 2 Sheets-Sheet 2 Patented Jan. 10, 1950 APPARATUS FOR EXAMINING GEMS AND CRYSTALS Harry L. Woodruif, Washington, D. C.

Application April 2.6, 1948, Serial No. 23,317

3 Claims. l

This invention relates to an illumination apparatus adapted to be used with a microscope for examination of gems and crystals.

An object of this invention is to provide an improved illuminator of relatively simple and inexpensive design adapted to be used for examination of gems and crystals.

Another object of this invention is to provide an improved illuminator of the dark field type adapted to be used for the examination of gems and crystals.

Still another object of this invention is to provide an illumination device of the dark eld type for examination of gems and crystals, the illuminating device being positioned in a housing that is attached to a frame that may be slidably positioned upon the stage support of a microscope.

A further object of this invention is to provide an illumination device'having a housing that is rigidly attached to the rotatable stage support of a gem and crystal examining microscope.

Other and further objects of this invention will be apparent to those skilled in the art to which it relates from the following specication, claims and drawings.

Referring to the drawings, briefly, Figure 1 is a view in partial section showing an embodiment of this invention; Figure 2 is a View of the top of the stage taken along the line 2-2 of Figure 1; Figure 3 is a detailed view in vertical section of the ring supporting the direct illumination mask over the light bulb and also the iris and the light polarizing element support; Figure 4 is a View showing the top of the element shown in Figure 3.

In Figure 1 this improved illuminator is shown in position for use with a binocular microscope having a back member I to which are attached the stage support II, the U-shaped foot I2 and the adjustable optical system I3 of the binocular type. The stage support l I is recessed to provide a ange I4 for slidably supporting the at plate I5 which may be removed from the stage support by sliding it to the front.

The lamp housing I6 is provided with a circular opening at the top thereof and the surface adjacent to this opening is soldered, brazed or otherwise attached to surfaces surrounding a corresponding hole formed in the plate I5. Thus the lamp housing I6 may be suspended from the plate I5 and the stage support II of the microscope. The lamp I'I may be of conventional incandescent 110 volt type or it may be of any other type desired such as the mercury vapor quartz lamp for giving light extending into the ultra vio- 2 let part of the spectrum. kThe lamp I1 is screwed into the socket I3 that is positioned in the bottom part of the housing' I9 that is detachably attached to the bottom of the lamp housing I6 so that the lamp may be 'readily removed and re-v placed. The housing portion I9 is made to f-lt into the opening between the U-shaped members I2 as illustrated.

The mask 20 is supported by the wires 2I a short distance above the lamp I'I so as to prevent direct light rays from proceeding from the filament of the lamp I1 upward through the opening at the top of the housing IE. Only reflected light rays are permitted to go from the lamp I'l upward to this opening and the inside of the housing I6 may be painted with highly reecting paint such as aluminum bronze to reflect the light from the side walls on the inside of the housing I 5 upward through the housing opening.

Wires 2I supporting the mask 20 are attached to the ring 22 that is provided with a shoulder 23 for engaging the lip of the mouth of the housing I6. The top surface of the mask 20 is painted with a dull black paint to minimizeA reflection therefrom. The ring 24 is attached to the plate I5 by means of the screws 25 so that the opening in this ring surrounds the ring 22. The outer surface of the ring 24 is beveled to cooperate with the inner beveled surface of the rotatable ring 26. The ring 26 carries a gem support consist-A ing of a post 2l attached to this ring by suitable screws, a sleeve V2B pivoted to the post 21 by the pin 2S, a slidable rod 30 sliding in the sleeve 28 and a gem engaging clip 3l attached to one end of the slidable rod 30. The gem engaging clip 3l is provided with tongs 32 for clinching the gem 33. The post '21 may be rotated so that the gem holding clip 3| may be swung in an arc over the rotatable ring 26 so that the gem' 33 may be brought into the desired position underA the microscope objectives. The rod 30 attached to the gem clip 3| also may be rotated so that the gem 33 may be rotated in a vertical arc underneath the microscope objectives. Furthermore, the sleeve 28 may be tilted in a vertical arc so that the gem 33 may be moved up and down and properly positioned under the microscope objectives and in the reflected light from the lamp I1.

Another ring 34 into which is tted iris 35, the opening 36 of which is adjustable by means of the lever 3l, is adapted to be positioned over the ring 22. The ring 34 is also provided with a ange 38 that is adapted to engage the top surface of the ring 22. Suitable fins 39 are provided to the bottom of the hole of the ring 34 which support a light polarizing element 4D of the Po1aroid" type. Other color lteis that are not polarizing may be inserted in place of the light polarizing element 40 if desired. The light polarizing element 40 functions to polarize the light from the lamp I'I before this light is transmitted to the gem 33 through the opening 36 y of the iris. The ring 34 sflpportilrg the lolarodl 40 lnfay be roe' tated so that the Polaroid 40 lis at right angles to a second Polaroid element 4I that functions as an analyzer element. The light polarizing element 4| is supported by the afin' $2 that is piv'e otly attached to the post 43 by the pin 44 where= by this light polarizing element 4I may be swung l in and out from under the microscopeobjectives. For this purpose the post 43 is attached toone of the corner portions of the plate I5 as shown in Figures 1 and 2.

A gemor crystal .33 supported by the holder 325 may be suitably positioned irl the light retiected from the inner Walls of the lamp housing I6 so that the optical properties or the gem or crystal S3 maybe thoroughly examined and determined. For this purpose the holder 32 may be provided with suitablegeinngripping tines, so that light may pass through the gem or crystal withoutbeing cut ofi or beingv obstructed by these tines. As previously described the holderl 32 may be Amoved sidewise, up and. down and it also may be rotated: so that thegeli- 35 may be examined from yari'usfsides Without rer'novingy it from the helder 32. Fiurtnemi6re,tnenolder 32 is support'd on the otatable ring; 2t that is rotatable iride pendentityA cfariy rottion imparted to the light polarizing" lment and in this manner the light polarizing and. dichroism of the gem or crystal may be dteriined, For this purpose the circumference of the ring may be provided with degree calibrations ranging from -360 degrees so that the angles' at which. light extinction is produced partoularlyin crystals may be determined. Fuiither'moe, theV light` polarizing element 40 may be otated ind-Ipendertlyiof` the gem or crystaly holdi` 3f so that this light polarizing element may be se't at right angles to-thejlight polarizing element 4|- or it may be set parallel to the light polarizing elemental if desired;

'The entire Yunit including the lamp housing I6,

the rotatable ring 26 and thel polarizing elements 40 and 4Ir as wellasthe holder 32 are supported by the plate I which may` be removed from the stage ci the microscope and is supported by the shoulder I4 of the-stage IIik As a result, other apparatus may be placed on the stage II if de# sir'ed. Furthermorda small glass dish 45 with an optically flat bottomV freeof strains may be provided for examination of gems or crystals immersel in liquids.

AWhile I Vhave-described this invention in detail with respect -to the embodimentillustrated it is, of course; to be understood that modications therein may be made without departing from the therein substantially concentric with said housing opening, means for attaching said housing to said plate, said plate being of such size as to removably t into the recess of the stage of the microscope so that said lamp housing is supported beneath the microscope stage and light is projected upward from said lamp through said openings, a rotatable ring supported by said plate, said rotatable ring being substantially concentric with said openings, a second ring removably and r0- tatably positioned in said openings, a light polarizing element positioned in said second ring to p'olarizelv the light transmitted out of said lamp housing by said lamp, an adjustable gem and crystal holder attached to said rst mentioned rotatable ring for holding the gems and crystals dineren-t positions over said light polarizing element in the eld of the optical system of the microscope, a second light polarizing element adaptedto be positioned above said gem and crystal' hldrs that the genis and crystals' may be supported and rotated between both' of said lightpolarizing elements', and arm pivoted tc said plate fr holding' said second light polarizing ele'- me't so that said second light polarizing element may be swung into position over the gems or crystals being examined.

2'.v apparalmsk forthe` exan'dmdtonL of gems and crystals' adapted to be usedY with a microscope misoroscope as a unit, comprising a lamp, a housing for said'V lamp, said housing having-an opening at' the top theredf', a plate" having opening Vtherein substantially concentric' with said` housing Jper1fllr'l'g',v means for attaching said housing tcs'aid plate, said plate being ef such size Y to prevent direct 'light frompassing out of said housing opening, anadjustahble gem and crystal holder attached to said' firstnlenticded rotambie ring for holding` the genis and crystals in different positions over said light polarizingv element, a second light polarizing element adapted tobe positioned over saidi gem and crystal holder so that the' gems and crystals may bes'upported and rotated between both of said light polarizing elements, and an arm pivotcd' to said plate for holding said second light polarizing element sor that "saidV second light y polarizing element may be swung into position over the gem or crystal beingv examined.

3. .Apparatus for the vexaminatior'i of gems and crystals adapted to beused with a microscope and removably supported on the stage of the microscope as a unit, comprising a lamp, a housing for said lamp, said housing having an opening at the' top thereof, a plate having an opening therein substantially the same size as said housing opening means for attaching said housing to said plate so that said openings are substantially` concentric, said plate being of such slee as tc removably' fit' into the recess of the stage of the inioosl S that Said lan'lp' housing is Supported beneath the microscope stage and light is projected upward from said lamp through said openings, a rotatable ring supported by said plate, said rotatable ring being substantially concentric With said openings, a second ring removably and rotatably supported in said open ings, a plurality of depending members attached to the bottom of said second ring and extending into said housing, an opaque plate supported by said depending members over said lamp to prevent direct light rays from passing through said openings from said lamp, a light polarizing element positioned in said second ring to polarize the light transmitted out of said lamp housing by said lamp, an adjustable gem and crystal holder attached to said first mentioned rotatable ring for holding the gems and crystals in different positions over said light polarizing element, a second light polarizing element adapted to be positioned over said gem land crystal holder so that the gems and crystals may be supported and rotated between both of said `light polarizing elements, and -an arm pivoted to said plate for holding said second light polarizing element so that said second light polarizing element may be swung into position over the gem or crystal being examined.

HARRY L. WOODRUFF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

